Both the Amazon Prime Rewards Visa Signature Card and the Costco Anywhere Visa Card by Citi cater to loyal shoppers of their respective retail giants, offering cash back on purchases made within their stores. If you're a frequent Amazon shopper, the Amazon Prime Rewards card may be better due to its high unlimited cash back at Amazon and Whole Foods.
However, the Costco Anywhere card edges out slightly with a higher cash back score, especially for gas, travel and dining. While the Amazon card is accessible to those with good to excellent credit, the Costco card demands excellent credit, making the Amazon card more attainable for a wider range of consumers.